This invention relates generally to safety protection devices and more particularly to methods and apparatus for protecting personnel on an oil drilling derrick.
Oil and gas exploration has been a hazardous undertaking since it began more than 150 years ago. During modern drilling rig operations, one of the times of greatest risk to personnel is when the rig is either running pipe into the well or pulling pipe out of the well. The “derrick man” is positioned up in the derrick (approximately 30 m) on a standard triple stand derrick. His job is to pull and rack the stands (three lengths of pipe joined together) of pipe into the racking board so the stands can be stored in an orderly arrangement. He is required to extend himself out from the racking board, retrieve the top of the stand, and guide it onto the racking board. The rig is usually equipped with at least one of several fall restraint and fall arrest devices in the event he should fall off the racking board. These could include devices such as a full body harness or fail arrest retracting device.
At times, the derrick man may forget to or is distracted from attaching to the fall protection system. This lack of attention could cause the derrick man to be severely injured, perhaps even fatally injured. Also, his fall may present a serious hazard to personnel on the rig floor.
Nevertheless, in normal drilling operations, personnel may be required to be in areas or jobs that are inherently hazardous. There are many safety systems on the market that are or can be effective if they are in proper and continuous use. However, rig operations start and stop repeatedly during any working shift. Thus, it is common for the derrick man to take his safety equipment off and on during his shift for breaks, for comfort while waiting on rig maintenance, to perform other functions that cannot be performed while hooked to the safety gear, or for other reasons. When operations restart, the derrick man may or may not remember to reattach all of his safety gear.
The person on the rig who is in charge of controlling operations is the driller. The driller cannot see all of the personnel involved in rig operations from his location, including the derrick man who may be located 30 m above him. Thus, the driller presently has no way of verifying that the derrick man is properly harnessed and ready to work every time rig operations are restarted.
Every known drilling company has specific policies regarding personnel safety during rig operations. OSHA also has regulations relating to these same issues. Insurance companies providing workers' compensation insurance have requirements for safety equipment that insureds must meet. But ultimately, safety depends upon whether personnel follow company policy and use the provided safety equipment.
Truly safe operations depend upon each of the rig hands being where they are supposed to be for any given rig operation. Because the driller is rarely, if ever, in a position to verify the location of all of the members of the crew during operations, it would be desirable to provide a comprehensive approach to monitoring crew behavior and location.
It is thus also be desirable to provide apparatus to make drilling operations safer. It is also desirable to provide apparatus that assist in changing the behavior of personnel to make safety systems more effective.